Acute optic neuritis associated with immunization with the CNS myelin proteolipid protein

Optic nerve tissue for SJL/J mice immunized with the central nervous system (CNS) myelin-specific proteolipid protein (PLP) was examined for histopathologic evidence of optic neuritis. Optic nerves isolated 17 d after immunization with PLP revealed an interstitial and submeningeal inflammatory infiltrate consisting of neutrophils and monocytes. In all cases, histologic evidence of optic nerve involvement correlated serologically with the presence of circulating anti-PLP antibodies. Control animals had no histopathologic evidence of disease or anti-PLP antibody. In many respects, the observed histopathologic profile of PLP-induced optic neuritis is similar to that associated with human inflammatory demyelinating diseases such as multiple sclerosis (MS). Because optic neuritis frequently is associated with some of the earliest clinical symptoms of MS, the acute nature of optic nerve involvement in this animal model suggests that immune recognition of the myelin PLP may play a significant role in the pathophysiology of optic nerve damage associated with sensitization to CNS-specific antigens.